nir: add and gather shader_info::writes_memory

for out-of-order drawing.

Acked-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4152>

src/compiler/shader_info.h

@@ -179,6 +179,9 @@ typedef struct shader_info {
    /* Whether flrp has been lowered. */
    bool flrp_lowered:1;
 
+   /* Whether the shader writes memory, including transform feedback. */
+   bool writes_memory:1;
+
    union {
       struct {
          /* Which inputs are doubles */